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Mariano Martín Editor
Alternative Energy Sources and Technologies Process Design and Operation AlternativeEnergySourcesandTechnologies MarianoMartín Editor
AlternativeEnergySources andTechnologies ProcessDesignandOperation
Editor MarianoMartín DepartmentofChemicalEngineering UniversityofSalamanca Salamanca Spain
ISBN978-3-319-28750-8ISBN978-3-319-28752-2(eBook) DOI10.1007/978-3-319-28752-2
LibraryofCongressControlNumber:2016930057
© SpringerInternationalPublishingSwitzerland2016
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Prologue Inthisbookweaimtopresenttheuseofalternativesourcesofenergyandtechnologiestoproducefuelsandpower.Wedescribethevaluechainfromharvesting therawmaterial(i.esolar,wind,biomassorshalegas),followedbytheanalysis oftheprocessingstepsintopower,fuelsand/orchemicalsand fi nallythedistributionoftheproducts.Wefocusonthechallengesofthesupply,thevariability ofthesourceanditsprediction,aswellastheuncertaintiesrelatedtoit,the descriptionofnovelprocessesthatarebeingdevelopedandevaluatedfortheir transformation,andthecurrentresultsonthetechno-economicanalysisthatare beingreportedintheliterature.Moreover,intermsoftheoperationofsuchsystems, energydistributiontotheconsumerandusage,andhowwecanintegratethenew chemicals,fuelsandpowerwithinthecurrentsystemandinfrastructureisevaluated.Anexampleoftheoperationofarealrenewable-basedsystem,ElHierro island(Spain)isalsodiscussed.
Theviewofthebookisgivenfromtheprocessperspectiveandhowaprocess systemsapproachcanhelpintheuseandintegrationofthesesourcesofenergyand noveltechnologies.
Ithankalltheauthorsforwithouttheireffortandcommitment,thisworkwould havenotbeenpossible.Specialthanksareduetothereviewersofthechapters,who haveprovidedusefulideasandsuggestionsandadifferentperspectivetothevarioustopicscoveredinthiswork.
November2015
PartIAlternativeEnergySources
NonconventionalFossilEnergySources:ShaleGas andMethaneHydrates ....................................3
MarianoMartín
RenewableEnergySector ..................................17
LeandroReal,EsperanzaSierraandAlbertoAlmena
PartIIInfrastructureDesignforVariousEnergySources
DevelopmentPlanningofOffshoreOilfieldInfrastructure ...........33 VijayGuptaandIgnacioE.Grossmann
EmergingOptimalControlModelsandSolversforInterconnected NaturalGasandElectricityNetworks .........................89 Nai-YuanChiangandVictorM.Zavala
PartIIIProcessingofAlternativesRawMaterials
Equation-BasedDesign,Integration,andOptimization ofOxycombustionPowerSystems ............................119 AlexanderW.Dowling,JohnP.Eason,JinliangMa, DavidC.MillerandLorenzT.Biegler
WindEnergy ...........................................159
JasonGanley,JieZhangandBri-MathiasHodge
SolarEnergyasSourceforPowerandChemicals ................181 LidiaMartín,BorjaHernándezandMarianoMartín
BiomassasSourceforChemicals,Power,andFuels ...............207 MarianoMartínandIgnacioE.Grossmann
CO2 CarbonCapture,Storage,andUses .......................235
Miguel ÁngelDelgadoandFabriceDelCorso
OptimalDesignofMacroscopicWaterandEnergyNetworks ........267
RamónGonzález-Bravo,FabricioNápoles-Rivera andJosé MaríaPonce-Ortega
PartIVOperations
Retro fitofTotalSiteHeatExchangerNetworks byMathematicalProgrammingApproach ......................297
Lidija ČučekandZdravkoKravanja
ImprovingEnergyEfficiencyinBatchPlantsThrough DirectHeatIntegration ....................................341
PedroM.Castro
LifeCycleAlgalBiore fineryDesign ...........................363 JianGongandFengqiYou
PlanningandSchedulingforIndustrialDemandSideManagement: AdvancesandChallenges ..................................383 QiZhangandIgnacioE.Grossmann
IndustrialToolsandNeeds .................................415 IiroHarjunkoskiandHubertHadera
Renewable-BasedSelf-sustainableOperationofIsolatedIslands ......439 MaríaCristinaRodríguez-Rivero
PartVEnergyDistribution
Multi-objectiveOptimisationIncorporatingLifeCycleAssessment. ACaseStudyofBiofuelsSupplyChainDesign ...................465 MaríaAugustaPáez,FernandoD.MeleandGonzaloGuillén-Gosálbez
Large-ScaleStochasticMixed-IntegerProgrammingAlgorithms forPowerGenerationScheduling .............................493 KibaekKimandVictorM.Zavala
Contributors AlbertoAlmena DepartmentofChemicalEngineering,UniversityofSalamanca, Salamanca,Spain
LorenzT.Biegler CarnegieMellonUniversity,Pittsburgh,PA,USA
PedroM.Castro FaculdadedeCiências,CentrodeMatemáticaAplicações FundamentaiseInvestigaçãoOperacional,UniversidadedeLisboa,Lisbon,Portugal
Nai-YuanChiang ArgonneNationalLaboratory,MathematicsandComputer ScienceDivision,Argonne,USA
FabriceDelCorso AirLiquide,JouyenJosasCedex,France
Lidija Čuček FacultyofChemistryandChemicalEngineering,Universityof Maribor,Maribor,Slovenia
Miguel ÁngelDelgado FundaciónCiudaddelaEnergia,CubillosdelSil(León), Spain
AlexanderW.Dowling CarnegieMellonUniversity,Pittsburgh,PA,USA
JohnP.Eason CarnegieMellonUniversity,Pittsburgh,PA,USA
JasonGanley DepartmentofChemicalandBiologicalEngineering,Colorado SchoolofMines,Golden,CO,USA
JianGong DepartmentofChemicalandBiologicalEngineering,Northwestern University,Evanston,IL,USA
RamónGonzález-Bravo ChemicalEngineeringDepartment,Universidad MichoacanadeSanNicolásdeHidalgo,Morelia,Michoacán,Mexico
IgnacioE.Grossmann DepartmentofChemicalEngineering,CarnegieMellon University,Pittsburgh,PA,USA
GonzaloGuillén-Gosálbez SchoolofChemicalEngineeringandAnalytical Science,TheUniversityofManchester,Manchester,UK
VijayGupta DepartmentofChemicalEngineering,CarnegieMellonUniversity, Pittsburgh,PA,USA
HubertHadera BASFSE,Ludwigshafen,Germany
IiroHarjunkoski ABBCorporateResearch,Ladenburg,Germany
BorjaHernández DepartmentofChemicalEngineering,Universityof Salamanca,Salamanca,Spain
Bri-MathiasHodge PowerSystemsEngineeringCenter,NationalRenewable EnergyLaboratory,Golden,CO,USA
KibaekKim ArgonneNationalLaboratory,MathematicsandComputerScience Division,Lemont,IL,USA
ZdravkoKravanja FacultyofChemistryandChemicalEngineering,University ofMaribor,Maribor,Slovenia
JinliangMa AECOM&NationalEnergyTechnologyLaboratory,Morgantown, WV,USA
LidiaMartín DepartmentofChemicalEngineering,UniversityofSalamanca, Salamanca,Spain
MarianoMartín DepartmentofChemicalEngineering,UniversityofSalamanca, Salamanca,Spain
FernandoD.Mele FacultaddeCienciasExactasyTecnología,Universidad NacionaldeTucumán,SanMigueldeTucumán,Tucumán,Argentina
DavidC.Miller NationalEnergyTechnologyLaboratory,Pittsburgh,PA,USA
FabricioNápoles-Rivera ChemicalEngineeringDepartment,Universidad MichoacanadeSanNicolásdeHidalgo,Morelia,Michoacán,Mexico
José MaríaPonce-Ortega ChemicalEngineeringDepartment,Universidad MichoacanadeSanNicolásdeHidalgo,Morelia,Michoacán,Mexico
MaríaAugustaPáez SchoolofChemicalEngineeringandAnalyticalScience, TheUniversityofManchester,Manchester,UK
LeandroReal EnergyEfficiencyDepartmentDirector(KPMG Inabensa (Abengoa)),Sevilla,Spain
MaríaCristinaRodríguez-Rivero DepartmentofEngineering,Universityof Cambridge,Cambridge,UK
EsperanzaSierra EnergyEfficiencyDepartmentDirector(KPMG Inabensa (Abengoa)),Sevilla,Spain
FengqiYou DepartmentofChemicalandBiologicalEngineering,Northwestern University,Evanston,IL,USA
VictorM.Zavala DepartmentofChemicalandBiologicalEngineering, UniversityofWisconsin-Madison,Madison,WI,USA
JieZhang DepartmentofMechanicalEngineering,UniversityofTexasatDallas, Richardson,TX,USA
QiZhang DepartmentofChemicalEngineering,CarnegieMellonUniversity, Pittsburgh,PA,USA
AlternativeEnergySources NonconventionalFossilEnergySources: ShaleGasandMethaneHydrates MarianoMartín
Abstract Theworldhasrunonfossilfuelsforthepast50years.However,the currentratesofdemandforenergyandthelimitedreserveshaveledtofocusour attentiononrenewablesources,insearchforsustainability,andnonconventional fossilfuels,shalegasandmethanehydrates.Shalegasisalreadyareality,but hydratesrepresentanevenlargerreserve,accountingfor50%ofthecarbonfossil sources.Theadvantageofunconventionalfuelsisthattheyarevirtuallythesameas conventionalones.Therefore,thetechnologytoprocessthemintoenergyand chemicalsisalreadywellknownanddeveloped.Ontheotherhand,theexploitation ofthesesourcesfacesimportanttechnicalchallengesintermsofsafeextractionand toavoidanyenvironmentalburdenasaresultofitsrecoveryfromtheground.In thischapterwepresenttheavailabilitiesofshalegasandmethanehydrates,the technologiesforitsrecovery,andtheeffectontheenergymarket.
1Introduction Inspiteofthecurrentefforttowardsmoresustainableproductionofenergy,until 1800,biomasssuppliedmorethan90%oftheenergyneedsofmankind.This positionofdominancedeclinedover120yearsduetothegrowthinthepopulation andtheindustrialdevelopment.Fromthe1920son,theeasyaccesstocrudeoiland itssimpletransformationintoready-to-usefuelsdisplacedtheuseofrenewables. Lately,socialconcernhasdriventheefforttowarddevelopmentofrenewable-based energy;seeFig. 1 (ExxonMobil 2013).
Overthepastyearstherehasbeenasteadyincreaseinenergyconsumption. Althoughthereisastrongcommitmentforrenewablesdevelopmenttoincrease theirshareintheenergymix,thetechnologyandinfrastructureforfossilsources hasimprovedoverdecadesandthus,renewablesareatadisadvantage.Therefore,it
M.Martín(&)
DepartmentofChemicalEngineering,UniversityofSalamanca, Plz.Caídos1–5,37008Salamanca,Spain
e-mail:mariano.m3@usal.es
© SpringerInternationalPublishingSwitzerland2016
M.Martín(ed.), AlternativeEnergySourcesandTechnologies, DOI10.1007/978-3-319-28752-2_1
isconvenientfortheindustrytocontinueusingtheinfrastructureavailableandthe transformationprocessesforpowerandchemicalsproduction.Recently,two sourcesofnonconventionalfossilfuelshavefocusedtheattention,shalegasand methanehydrates(MacDonald 1990).Actually,bothrepresentalternativesources fornaturalgas,whichcanbeeasilyintegratedwithinthecurrentsupplychain.
2ShaleGas Shalegasisnaturalgasthatistrappedwithin fi ne-grainedsedimentaryrocksknown asshaleformations.Inspiteoftherecentmediaattention,shalegashasbeen extractedformorethanacentury.Asearlyas1821inFredonia,NY,shalegaswas extractedfromfracturesintheground.Itwasnotuntilthe1920sthatatechnologicalbreakthrough,thedevelopmentofhorizontaldrillingandhydraulicfracking, acceleratedtheextractionofshalegas.Theuseofmicroseismicmonitoringtechniquescertainlyalsocontributed(Siirola 2014).The fi rstfrackingintheUScanbe datedbackto1947.However,theindustrialexploitationofshalegasismorerecent, aroundthe1970s.Bythattime,shalegasdrillingwasnotprofitable.Sincethenand togetherwiththedevelopmentinoilextraction,theDepartmentofEnergyand somecompanieswereabletocompleteasuccessfulair-drilledmulti-fracturehorizontalwellinshalebackin1986.The firsteconomicallyviableproductionofshale gaswasduetoMitchellEnergy,whichin1998developedtheslickwaterfracturing andshalegasstarteditscontributiontothenationaleconomyoftheU.S.(EIA 2012;Krauss 2009;USEIA 2011;Stevens 2012;WhiteHouse 2009;Huges 2011; Wangetal. 2014).InFig. 2 weseetheavailabilityofshalegasacrosstheworld. China,theUS,Argentina,andMexicohavethelargestreserves.
Fig.1 2013Theoutlookforenergyaviewto2040. Source ExxonMobile(2013)
2.1GasExtraction Theextractionofshalegasiscarriedoutusingthetechnologyknownasfracking.It consistsofhorizontaldrillingandhydraulicfracturingsothattherockisbroken downusinga fluid.Thedevelopmentofthetwotechniques,actuallywithintheoil andgasindustry,andtheirapplicationtotheparticularcaseoftheshaleformations iswhathasenabledtheextractionofshalegas.Figure 3 showsa3-Dimageofthe designofthedrillingsystem.Ina firststep,verticalperforationisusedtoreachthe shaleformations.Onceatthatlevel,horizontaldrillingbegins.Next,waterwitha numberofdifferentcompoundsisinjected.Thus,therockisfracturedandthegas canbeextracted.
Theaimofinjectinga fluidathighpressureistoextendthefractures.This fluid alsocarriesproppantwheninjectedintotheshaleformation.Thepurposeofthe proppantistomaintainafractureopen,avoidingdamageintheformationorthe well.Silicasand,resin-coatedsand,orman-madeceramicsarethemostused.Two alternativestotransporttheproppantcanbeused,eitherahighviscosity fluidora high flowrate.The firstonegenerateslargefractureswhilethesecondonecauses smallmicrofracturesintheformation.Thelatterhasbecomethemethodofchoice.
The fluidisnotpurewater,butanumberofchemicalsareaddedtoefficiently delivertheproppant.Thetypicalcompositionis90%water,9.5%issand,and chemicaladditivesupto0.5%(GroundWaterProtectionCouncil,GWPC 2009). Chemicals(3–13)(GWPC 2009;API 2010)aretypicallyaddedincludingacids, NaCl,polyacrylamide,ethyleneglycol,boratesalts,sodiumandpotassiumcarbonates,glutaraldehyde,guargum,citricacid,andisopropanol.Table 1 showsthe purposeofeachofthechemicalsused.Theinjectionofwatercontainingthese chemicalshasarisenconcernonthepollutionofdrinkingwaterandreservoirs (Wangetal. 2014).Darrahetal.(2014)foundthatthefracturingoftherockswas notresponsibleforleakingbuttheconstructionofthewellsthatallowsgasoroil leaks.Thereservoirscanbefoundataround3000mwhilewaterresourcesareat
Fig.2 Mainshalegasreservesworldwide(US.EnergyInformation)
Fig.3 Shalegasdrillingand extraction(adaptedfrom: MEPL 2015;BlogPreston 2011;Wangetal. 2014)
Table1 Purposeofthechemicals
AcidsCleaning
NaClDelaysbreakdownofthegelpolymerchains
PolyacrylamideReducefrictionpipe fluids
EthyleneglycolPreventsdepositsinthepipe
BoratesaltsMaintain fluidviscositywhenthetemperatureincreases
Na2CO3,K2CO3
Maintainingeffectivenessofcrosslinkers
GlutaraldehydeDisinfectants
GuargumIncreases fluidviscosity
CitricacidCorrosionprevention
IsopropanolIncreases fluidviscosity
about200mandthepipingsystemtypicallyreaches350mdeeptoavoidsuch contamination.However,Llewellynetal.(2015)havereportedacasewhere contaminantshavemigratedlaterallythroughkilometersofrockaffectingapotable wateraquifer.Furthermore,thereisanotherconcernregardingwaterissues.Alarge amountofwaterisusedtoextractthegas.Ninety-sevenbilliongallonsofwater
Fig.4 Gastreatmentatthewell(adaptedfromGoellner 2012)
wereusedtofrackthe39,294oilandgaswellsdrilledfrom2011to2014,mostof theminregionswithwaterscarcity(Ceres 2014).
Thegasextractedcontainsanumberofimpuritiesthatmustberemovedbefore injectingitintothenaturalgaspipeline.Figure 4 showsthetreatmentstages.First, thegasisseparatedfromtheliquidusedforextraction.Next,sourgasessuchas CO2 andH2Sareremoved.Subsequently,thegasisdehydratedtoremovethe remainingwater.Finally,mercuryandnitrogenareremoved.Afterthispoint,the naturalgasisseparatedfromtheheavierfractions,thewetfraction.Ifthewet fractionationiseconomicallyfeasible,thentheshalegascanbeusedasasourceof differentchemicals.Inparticular,ethaneisveryinterestingasarawmaterialforthe productionofethylene,themajorbuildingblockforpolymers,suchaspolyethylene,polystyrene,PVC,etc.,aswellasintermediateforotherchemicalslike ethyleneoxide,ethyleneglycol,etc.(Siirola 2014).
2.2Composition Thecompositionoftheshalegas(mainlymethane,ethane,propane,CO2,and nitrogen)variessignifi cantlyfromsitetositeoftheactuallocationofthewell,not tomentionbetweendifferentallocations.InTable 2 wepresentthecomposition
Table2 GascompositionofdifferentformationsacrosstheU.S.
ComponentMarcellusAppalachiaHaynesvilleEagleFord Methane97.13179.08496.32374.595
Ethane2.44117.7051.08413.824
Propane0.0950.5660.2055.425
C4+0.0140.0340.2034.462
Hexanes+0.0010.0000.0610.478
CO2 0.0400.0731.8161.536
N2 0.2792.5370.3690.157
Total100.0100.0100.1100.5
HHV(BTU/SCF)1031.81133.21009.81307.1 Wobbenumber1367.11397.01320.11490.0
fromdifferentplays.Inparticular,thecompositionsweretakenfromshaleplays thatsupplygastothetransmissionnetworkandend-users,includingtheAntrim, Barnett,Fayetteville,Haynesville,Marcellus,andNewAlbanyplaysasmeasured in2009(GeorgeandBowles 2011;BullinandKrouskop 2009).Wetshalegasis definedastheonethatcontainsC2+fractions,anddrytheonethatdoesnot.
Theuseofthisshalegasasnaturalgasismeasuredbycomparingcertain characteristicparameterssuchastheWobbenumber,theenergycontent,whichis limitedto1,400Btu/scf,theheatingvalue,whichshouldbearound1,100Btu/scf, theupperlimitonC4+tobein1.5mol%andupperlimitsforinerts,4%.Apart fromthesespeci fications,theoperatorofthepipelinecandeclinetotransporta certaingasifthereisfoundrisktocausecorrosion,declaringittobe “out-of-tolerance.” Otherwise,thenaturalgasesfromshaleformationsareincluded inthenaturalgassupplychain.Therearemainlyfourcustomersforthenaturalgas, thepowersector,theindustrialsector,commercial,andresidential.IntheUS,they represent34,31,14,and21%respectively(TheBreakthroughInstitute 2011).
Apartfromasourceofnaturalgas,thewetfractionprovidesethane,propane, butane,etc.Theseparationofthesecomponentsrequiresadditionalinvestment.Of particularinterestistheethane,whichcanbeusedinsteamcrackingunitsto produceolefins,ethylene,andpropylene.Thesechemicalsarethemonomerof plasticssuchaspolyethylene(PE)andpolypropylene(PP)thathaveawiderangeof applications(Siirola 2014).Theproductioncostisthemainadvantageofethane productsincomparisontotheproductionofthesamechemicalsfromnaphtha (Goellner 2012).
2.3ShaleGasProductionCost Thecostsperwellrangefrom$2to$9millionintheUSorArgentinaversus$5to $20millioninEurope(Philippe 2013)andthecosthasdecreasedfromtheoriginal $50million(Cué 2015).Forcomparison,aregularwellforcrudeoilcosts$2 million.Furtherdevelopmentoverthenext5–10yearsisexpectedtocutthese pricesbyhalf.Intermsofthepriceoftheshalegas,inEuropeitisexpectedtobe between$6and$15.5/MMBTU(Growitchetal. 2013),intheUSvaluesfrom$3.4 to8.75perMMBTUcanbeobtaineddependingontheplaceofproduction (BermanandPittinger 2011;MIT 2009;Glickman 2014),whileinChinavaluesof $11.2/MMBTUarereported(Glickman 2014).
3MethaneHydrates 3.1AvailabilityofMethaneHydrates Methanehydrates,orclathrates,areacage-likelatticeoficeinsideofwhich moleculesofmethanearetrapped,seeFig. 5.Ifthehydrateiseitherwarmedor depressurized,itbecomesasourceofwaterandnaturalgas.Typically,onecubic meterofgashydratereleases172m3 ofnaturalgas,whenbroughttoEarth’ssurface (Ichikawaetal. 2007).Themethanethathasbeentrappedintoicehastwomain origins,biogenic,createdbybiologicalactivityinsediments,andthermogenic, createdbygeologicalprocessesdeeperwithintheEarth.Hydratedepositsmaybe severalhundredmetersthickandgenerallyoccurintwotypesofsettings:under Arcticpermafrost,andbeneaththeocean flooronthecontinentalmarginsat500m deepwherenutrientrichwatersareusedbybacteriatoproducemethane,seeFigs. 6 and 7.Theinterestinhydratesisnotnew.Thepetrochemicalindustryhasbeen interestedinthemfromthe1930swhentheyrealizedthatthehydrateswere blockingtheoilpipes.Laterinthe1960s,Russiandrillersdiscoveredthepresence ofhydratesingas fieldsinSiberia.The firstproduction fi eld,Messoyakha,was discoveredin1968justabovethefreegasreservoirs.Inthe1970smethanehydrates werealsofoundindeepwaters.Actuallythehydratesrepresent50%ofallthe hydrocarbonresourcesknownintheworld,seeFig. 8 (Kvenvolden 1993;Dillon 1992;Trehuetal. 2006;BoswellandCollett 2011).
3.2MethaneHydratesExtraction Hydratesoccurattemperaturesbelow295Kandabove3000kPa.However,the dissociationofthemethanehexahydraterequiresexternalenergy.Therefore,three alternativetechnologieshavebeenproposedeitherthermalrecovery,
Fig.5 Icelatticeformethane hydrates. http://woodshole.er. usgs.gov/project-pages/ hydrates/primer.html
Fig.6 Typicalallocationofmethanehydrates(adaptedfrom http://energy.gov/fe/scienceinnovation/oil-gas-research/methane-hydrate )
Fig.7 Allocationofthemethanehydratesreservoirs(Source http://www.utexas.edu/news/ files/ Map-hydrates-canada1.jpg )
Fig.8 Organiccarbon availabilitybytype
depressurization,ortheuseofchemicals(XuandRuppel 1999;Ruppel 2007, 2011),seeFig. 9 foraschemerepresentationofthethreeoptions.
The firsttechnologyconsistsofinjectingsteam,hotbrine,orwatertomeltthe icesothatthegasisreleased.Theliberatedgasascendsthroughthepipe.Although themethodissimple,heatingupthe fluidstobeinjectedisexpensiveandthe fluid temperaturecandropbeforereachingthereservoirduetothehigh-energylosses.
Thesecondalternativeistorelievethepressuresothatthegas flowsout.Thisis carriedoutbydrillingintothebedswheregasmethanecanexistbeforeforming hydrates.Bychangingthelocalpressuregradientwithinthesedimentbeds,the gaseswill flowtoawellhead.Threemechanismsgovernthedepressurizationofthe gashydrates:(1)kineticsofdissociation,(2)conductiveheattransfer,and (3)convective flowof fluidslikegasandwater.Thegasesareself-drivenbutitis lesspredictablethanothermethods.Furthermore,thedissociationofthehydrateis anendothermicprocessthatcanfreezethesedimentsandthemachinery.
Finallywecaninjectchemicalssuchasmethanol,monoethyleneglycoland diethyleneglycol,orbrines.Byalteringthecompositionofthewater,thehydrate becomesunstableandthusthegascanbereleased.Furthermore,thechemicals couldlowerthefreezingpointofthewaterinthesurroundings,andthegaseswould becollectedbythesamewellhead.Actually,insteadofmethanolorotherchemical wecoulduseCO2 toreplacethemethaneinthehydrates.Inthisway,CO2 isnot onlycapturedbutisusefultorecoverthevaluablemethane.Itispossibleto exchangeupto64%ofthemethanebyCO2.Theprocessisexothermic,sincethe heatofformationoftheCO2 hydrateishigherthantheheatofdissociationofthe CH4 hydrate.Thus,theexchangeisthermodynamicallyfavorablebutthekineticsis slow(Ohgakietal. 1996).
Althoughthetechnologyisfeasible,itisstillnotreadyatindustrialscaleandit facessomeimportantchallengessuchasleakagecontrolandmethanereleasetothe atmosphere.Foreaseofexploitationofthevariousallocationswherehydratesare found,theordercouldbe(i)sub-permafrosthydrates,(ii)offshoreaccumulations
Fig.9 Methodsformethanefromhydratesextraction(adaptedfromRuppel 2007)
closetoconsumers,and(iii)remoteoffshoreaccumulations.Currently,thecountriesthatareactivelyworkingonthedevelopmentoftechnologiestoextractthis methaneareJapan,SouthCorea,India,China,andtheUnitedStates(Collectetal. 2008, 2009, 2011).
3.3ProductionCostofNaturalGasfromHydrates ThecurrentcostofgasproducedfrommethanehydratesisestimatedtobeUS$30 toUS$50permillionBritishthermalunits(MMBTUs),whichisanorderof magnitudelargerthanthecurrentHenryHubprice,aroundUS$6perMMBTU. TheInternationalEnergyAgencyestimatesthatonceeffi cientpracticesandprocessesaredeveloped,naturalgasproducedfrommethanehydrateswillcost betweenUS$4.70andUS$8.60perMMBTU(SpaldingandFox 2014)becoming competitiveandattractive.
4NaturalGasMarket.EffectofUnconventionalGas Overthepastyears,thepriceofnaturalgashasoscillatedwithinawiderange (GeorgeandBowles 2011)ascanbeseeninFig. 10.Notethattheexploitationof shalegasbeganin2009resultinginasharpdecreaseinthecostofnaturalgas followedbyacutinpowerprices.
Asaresultoftheshalegasavailability,theproductionofshalegasisprojected torepresentalmosthalfofthetotalproductionofnaturalgasinthenext15years,as presentedinFig. 11 (GeorgeandBowlesLiss 2012;BusinessInsider 2012).Inthis figurethecontributionofthehydratesofmethaneisnotincluded.Hydratesare
Profileofcostofnaturalgas. Source U.S.EnergyInformationAdministration(Oct.2008)
Fig.10
Fig.11 Expectedcontributionofshalegastothenaturalgasmarket(EIA 2012). Source U.S. EnergyInformationAdministration(Oct.2008)
beginningtobeexploitedcommerciallybyJapanduetotheneedforenergy sources,butnofutureestimationofthecontributiontothemarketisavailable. Furthermore,inthefollowingyearsthedeliveredpriceisexpectedtoincrease from$6.5/thouscuftto$9.5thouscuftin2035(EIA 2011),seeFig. 12
Fig.12 Expecteddeliveredpricesfornaturalgas. Source U.S.EnergyInformation Administration(Oct.2008)
References AmericanPetroleumInstitute(2010) FreeingUpEnergy.HydraulicFracturing:Unlocking America’sNaturalGasResources http://www.api.org/policy/exploration/hydraulicfracturing/ upload/HYDRAULIC_FRACTURING_PRIMER.pdf
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RenewableEnergySector LeandroReal,EsperanzaSierraandAlbertoAlmena
1Introduction Somerenewableenergysourceshavebeenusedbyhumanityfromthebeginningof itsexistence,especiallybiomass,solarenergy,windenergy,andhydraulicenergy. Wecan findsomeexamplesforthetraditionaluseofenergyresourcesinsailing,in thewindmillsandwatermills,orintheconstructivedispositionsofbuildingsto harnessthesolarpower.However,theinventionofthesteamengine,atatimewhen therewasnoconcernaboutthedepletionofnaturalresources,supposedtheendof theseenergeticuses.
Nevertheless,inthedecadeofthe70s,renewableenergieshadanupturnasan alternativetofossilfuels.Besides,theconcernaboutthelimitedquantityoffossil fuelsandtheirenvironmentalimpact,togetherwiththeenergeticcrisisofthis decade,ledtotheappreciationoftherenewableenergiespotentialbybothgovernmentsandresearchers,inordertosupporttheenergeticdemand.
Thischaptercontainsareviewofthehistoricevolutionofeachtechnology,from theirrudimentaryuseinthepastuntilnowadays.Italsoanalyzestheimprovement andthefuturepotentialitiesofeachkindofenergyproduction.
L.Real(&) E.Sierra EnergyEfficiencyDepartmentDirector(KPMG – Inabensa(Abengoa)), Sevilla,Spain
e-mail:leadudo@gmail.com
A.Almena
DepartmentofChemicalEngineering,UniversityofSalamanca, Plz.Caídos1–5,37008Salamanca,Spain
e-mail:almena@usal.es
© SpringerInternationalPublishingSwitzerland2016
M.Martín(ed.), AlternativeEnergySourcesandTechnologies, DOI10.1007/978-3-319-28752-2_2
2SolarThermalEnergy 2.1LowandMedium/HighSolarThermalEnergy Atthispointwearefocusingonthehistoricdevelopmentandtheimprovementin theefficiencyofthecurrenttechnology,usedcommerciallyforheating fluidsupto low(<100 °C)andmediumtemperature(100 °C< T <300 °C):thesolarcollectors.
Itisdifficulttospecifyexactlyatwhatpointhumansstartedtoharnessthesolar thermalenergytoheat fluids,unlikethephotovoltaicsolarenergyofwhichwe actuallyknowthedateofdiscovery.Wecansaythatsolarthermalenergyhas alwaysbeenused,toagreaterorlesserdegree.However,wecanknowexactly whenthistechnologystartedtobedevelopedforthatpurposeandtoimprovethe efficiencyoftheseprocesseshasbeenimproved.
Thedesignofthe fi rstsolarcollectorwasfoundin1767,whenHoracedeSaussure, aSwissnaturist,inventedtheself-named “hotbox”,comprisingaboxwithitsinside coloredinblackandinsulationinallitswalls,withtheexceptionofthesuperiorface thatwasmadeofglass.Thisdevicemadeitpossibletoachievetemperaturesupto 109 °C.However,itwasnotuntil1891thatthe firstpatentofthisinventionwasmade, thewaterheaterClimax,capableofheatingwaterwithsolarpowerinaneffi cient enoughwaytoensureawideuse,especiallyinthesunnyregionsoftheU.S.A.Laterin 1909,anindependentaccumulationdevicewasincludedintothedesigntoallowthe storageoftheheatovernight,constitutingthe firstthermosiphonsystem.
Unfortunately,thediscoveryoffossilfuelsandthefallinpricesoftheirproductionstoppedthedevelopmentofsolartechnologywhich,justliketheother renewableenergies,peakedcoincidingwiththesubsequentenergycrisis.Itcanbe affirmedthatthe70s’ energycrisismarkedaturningpointintheevolutionofthe waterheatingtechnologiesbysolarpower.
However,althoughthecrisiswasovercomeandthepricesoffossilfuelswere controlled,theinvestmentanddevelopmentofnewsolarenergytechnologies continued,butinaslowerway.Thus,thistimethetechnologicaldevelopmentwas notsuspendedagain.
Below,themostextensivetechnologicalsolutionsfor fluidheatingbysolar energyatlow,medium,andhightemperaturesareshown.
2.1.1LowTemperatureSystems FlatPlateCollector
Thiskindofdeviceisprimarilyusedworldwide.Itstechnologicaldevelopmentcanbe consideredasoptimal,buttheresearchinthis fieldiscurrentlylookingfornew materialswhichcouldimproveitsefficiency,byprovidingbetterpropertiessucha betterheatinsulation,anincreaseofgreenhouseeffectbyusingglassmaterials,abetter designintheregulationandcontrolsystems,orbyreducingthemanufacturingcosts.
Theevolutionofthesolarcollectorsyieldhasbeenhistoricallybondedtotheir marketgrowth.Thisaffirmationcanbesupportedbytwofacts:theevolutionfroma craftsmanshiptoamassproduction,causingacostreductionandtheapplicationof qualitysystems;andtheincreaseinthedirectinvestmentfromdifferentmanufacturers,whichallowedtheproducttobeimproved,becomemorecompetitive,and increasetheirmarketshare.
Inadditiontothisperformanceimprovementofthesolarcollectors,alsoimportantprogresseshavebeenachievedintheauxiliarysystems,suchasanupgrade intheinsulationofthestoragesystems,amoreefficientpumping,theintroduction ofregulationandcontrolsystems,andtheuseofwarningdevicesaboutfailureand malfunction.
2.1.2Medium/HighTemperatureSystems VacuumTubeCollector Thiskindofcollectorhasalessmarketsharethanthe flatplateones,duetotheir highermanufacturingcostandsellingprice.Despitethevacuumtubecollectors haveaperformancerangefrom50to200 °C,theiroptimalefficiencyisfarfromthe standardusefordomestichotwaterproductionandheatingapplications,sotheyare usedforthispurposeonlyinthoseregionswithlowsolarradiation,accordingto theirgreateruptake.Thus,thesecollectorsaremoreusefulinindustrialprocesses, wheretheyhavetocompetewithothertechnologiesthatachievehighertemperatureandmaintainabettercost/yieldratio.
Theefficiencyimprovementofthistechnologyfollowsthesametrendand constraintsasthosesetforthesolarcollectors.
Cylindrical-ParabolicCollector Talkingaboutthehistoricdevelopmentof fluidheatingbytheuseofsolarpower,it isworthmentioningMouchot’ssteamengine.Thistechnologyconsistsofalarge parabolicreceivercoveredwithmirrors,whichconcentratestheradiationatonly onepoint.Theheatgeneratedbythisdeviceisabletoactivateasteamengine.This inventioncanbeconsideredastheprecursortothesolarthermalenergyconcentrationtechnology,inwhichtheparaboliccollectorsarebased.Thisdevicecanheat athermal fluidbyconcentratingthesolarenergyatonepoint(astheMouchot’s machinedoes)orinoneline.
The firstinstallationofaparaboliccollectorwasin1912,beingitspurposethe generationofsteamfortheoperationofawaterirrigationpump.Furthermore,there arecommercialplantsusingthistechnologysincethe80s.
Effortsonincreasingtheperformanceofthistechnologyfocusesonthe improvementofthereflectionandrefractionofthecollectorsandthesearchforthe internal fluidwiththebestfeatures.Inaddition,therearealsoauxiliary fieldsthat
canbeimprovedforthispurpose,suchasthecontrolsystems,theperformanceof theelectricenergyproductionsystem,thesolartracking,etc.
2.2HighTemperatureSolarEnergy.SolarThermal PowerPlants Thiskindoftechnologyhasonlybeendevelopedinthemodernage,existingsolar energyplantsarebasedoninthisknowledgesincethe60s.However,the fi rst commercialplantinSpaincameoutin2007.ThePS10wasbuiltinSeville, designedwithapowerof11MW.Thereafter,solarthermalpowerplantshaveseen anexponentialgrowthandtheyhavebeendevelopedwithimprovedattached technologiestoenhancetheiryield,becomingabigcontenderforconventional plants,thankstotheirversatility.
Unlikelowandmediumtemperatureapplications,whichhaveasimplerprocess ofheating fluidsuptomoderatetemperatures,hightemperaturesolarsystemsare basedonmorecomplexprocessestoheattheworking fluiduptohighertemperaturestoproduceenergy;hencetherearemoreelementsinvolvedinthewhole process,namelyturbines,enginesforheliostats,steamgenerators,etc.Thistechnicalcomplexity,togetherwithhavingmoredeterminingfactors,hashampered innovationinthissector,whilethelowandmediumtemperatureapplicationsmay haveledtothedevelopmentofdifferenttechnologieslike flatplatecollectors, vacuumtubecollectors,parabolic-cylinders,thermosiphon,orforcedsystems. Thus,thearchitecturaldesignsoftheseplantsandtheoriginalbuildingsolution havenotbeenalteredsignifi cantly,sothatthesuccessfultechnologicalinnovation isfocusedontheimprovementoftheprocessitself,andnotinthedevelopmentof attachedtechnologies.Someexamplesoftechnologicalimprovementofthese plantsareshownbelow:
• Storageofmoltensalts the fi rsthightemperaturesolarthermalpowerplantsjust heateda fluidwiththeradiationofthesun,stoppingtheelectricpowergenerationwhenthesolarradiationceased.Thissupposesanonmanageableenergy production,whichmeansacompetitivenesslossrelatedtoconventionalpower plants.
The firstmoltensaltthermalstorageplantinSpainwasbuiltinSeville,in2011. Thus,itsupposesthe firstsubstitutionofthecirculating fluidtoamoltensalt fluidonacommercialscale.Thenew fluid,besideshavingacirculation behaviorsimilartothesubstitutedone,alsohashigherspecifi cheatandallows easystorageofthesalts.Thankstothisinnovation,theenergyproduction becomesmanageableandcanthereforeadapttheproductiontothedemand duringsunnyhours,aswellaskeepingtheenergyproductionwhenthereisno sunlight.Thisfactnotablyimprovesitsversatilityandabilitytocompetewith conventionaltechnologies.
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